Assigistoe to the



(No Model.) 5

S. OAKMAN.

TELEGRAPH INSULATORn No. 288,360. Patented Nov. 13,1883.

I WlTN E5555 INVENTUR 3o repellent.

UNITED STATES PATENT OFFICE.

SAMUEL OAKMAN, OF MELROSE, MASSACHUSETTS, ASSIGNOB TO THE AMERICAN INSULATOR COMPANY, OF NE YORK.

TELEGRAPH-INSULATOR.

SPECIFICATION forming part of Letters Patent No. 288,360, dated NovemberlS, 1585. Application tiled July 30, 1853. (No model) and useful Improvements in Telegraph-Insulators, of which the following is a specification.

My invention relates to that class of glass insulators which are supported upon screw: pegs, and has for its object to so construct the interior of the insulator that it shall have a broad interior band of weatherprotected surface for insulation between the exterior of the insulator and the supporting-peg; also, in providing the interior of the insulator with 1 an annular recess for the reception of paraffine or some similar moisture-repellent. These objects I attain by the mechanism illustrated in the accompanying drawings, in which Figure l is an elevation of one of my insulators, and Fig. 2 is a cross-vertical section of the same.

In the drawings, A B 0 represent the body of the insulator. This insulator has a screwthread, D, formed on its interior, as shown 2 in Fi 2 of the ordinar 7 st le and dimen- 5 z: a 5 y sions of the standard insulators now in general use. I also form on the interior surface an annular recess, 0, which serves to receive a coating or body of parafline or other moisture- Immediately below the recess 0 I form the annular shield E and the upwardlyprojeeting recess H.

By the above-described construction I attain, in connection with the internal screw, D, an interior insulating-surface, l 2 3 4 5 6, Fig. 2, apart of Whichviz., the part 2 3is especially adapted to receive and retain paraffine. Another partviz, ,the part 3 t-is doubly protected from the weather; and a third part, 4 5 6, adds to the interior insnlating-surtace.

The arrangement of the interior of a screw insulator, as above described, gives a great advantage over the ones now in use. By ioI am enabled to obtain in a single moderate sized insulator all of the advantages of the diiferentstyles heretofore in use.

Having thus described my invention, what I desire to secure by Letters Patent is 1. A glass insulator having formed within its interior a screw-thread, D, recess C, shield E, and recess H, all substantially as described, and for the purpose set forth.

2. A glass insulator, having formed within its interior a screw-thread, D, shield E, and recess H, in combination with the screw-peg P, all substantially as described, and for the purpose set forth.

FRANK G. PARKER, WILLIAM EDSON. 

